1. Field of the Invention
The present invention relates to an RF transceiver module, and more specifically, to an RF transceiver module formed in a multi-layered ceramic with an RF transceiver IC.
2. Description of the Prior Art
Radio frequency (RF) communication modules are commonly used in wireless communication devices such as cellular phones. Typically, RF communication modules are capable of transmitting and receiving over multiple bands, with dual-band and tri-band RF communication modules being the most popular.
Please refer to FIG. 1. FIG. 1 is a functional block diagram of a prior art RF communication module 10 of a wireless communication device. The RF communication module 10 comprises an antenna switch 12, a set of SAW filters 14, and a receiver 16. When the RF communication module 10 receives RF signals from an external antenna 11, the antenna switch 12 is switched such that the RF signals pass from the antenna 11 to the SAW filters 14 through the antenna switch 12. The received RF signals are then filtered by the SAW filters 14, and sent to the receiver 16. The receiver 16 then amplifies, converts, and demodulates the signals before sending them to the DSP 18 for digital processing. The RF communication module 10 further comprises a transmitter 20 and a set of power amplifiers 22. To transmit voice or data signals, the DSP 18 first sends signals into the transmitter 20. The transmitter 20 then modulates and up-converts the signals, and sends them to the power amplifiers 22 for amplification. The antenna switch 12 is then switched to allow the amplified RF signals to pass from the power amplifiers 22 to the antenna 11 through the antenna switch 12.
Unfortunately, each function in the prior art RF communication module 10 shown in FIG. 1 is realized by separate modules or ICs. These modules or ICs are typically connected together on a printed circuit board (PCB). Having many modules formed on a PCB leads to many problems. First of all, the result is higher assembly cost and takes up a large area on the PCB. Second, the complex wiring between these modules leads to unwanted cross talk and radiated emission problems. Third, each module is made using a different manufacturing process, and electrical characteristics can vary widely as a result. These inconsistent characteristics make tuning and calibrating the RF communication module 10 difficult.
Please refer to FIG. 2. FIG. 2 is a functional block diagram of a prior art RF communication module 30 with an integrated front-end receiver 32 (disclosed in U.S. Pat. No. 6,289,204 B1, “Integration of a Receiver Front-end in a Multilayer Ceramic Integrated Circuit Technology”, by Estes et al.). The front-end receiver 32 includes the antenna switch 12, the SAW filters 14, and the receiver 16. The RF communication module 30 has exactly the same functionality as the RF communication module 10 of FIG. 1. The difference is that the front-end receiver 32 is formed on a single multi-layer ceramic substrate. This compact packaging offers advantages in size, weight, and cost. However, the receiver 16 and the transmitter 20 are still formed as separate modules. Separating the receiver and transmitter leads to larger circuit area, higher circuit wiring complexity, and difficulty in tuning and calibrating the RF communication module 30.